Endoscopic suturing needle

ABSTRACT

A suturing needle is illustrated which can engage a suture to an outer housing, thereby presenting a relatively smooth surface at the distal end of the apparatus to minimize tissue trauma. A lock feature prevents unexpected extension of the needle from the outer housing which could release the suture. A finger switch is used to overcome the locking mechanism when it is desired to release the suture. The distal end of the housing and the needle are a generally similar flat profile to minimize uneven edges which could damage the tissue. The suture is retained in a hook located in the needle, the opening for which is retracted in the housing to retain the suture.

This application is a continuation of application Ser. No. 07/914,810,filed Jul. 16, 1992, now U. S. Pat. No. 5,312,422.

FIELD OF THE INVENTION

This invention relates generally to the field of medical instruments andmore particularly to an endoscopic suturing needle that is used toinsert a suture within the body of a human being or of an animal.

BACKGROUND OF THE INVENTION

Manually operated medical and surgical instruments provide surgeons withthe capability of emplacing or removing sutures. Some of the devicesenable surgeons to grasp suture needles within the procedural field.These instruments have jaws at the distal end, which allow the needle tobe trapped and removed. Surgeons utilize these various devices whenthere is limited accessibility within the procedural field. To alleviatelarge incisions, which involve a higher morbidity due to increasedtrauma to surrounding tissue and a higher incidence of complications,endoscopic procedures have become preferable methods of accessingvarious surgical sites. The suture devices are utilized in endoscopicprocedures in order to achieve hemostasis after the removal or biopsy ofan organ.

The instruments that are typically used to suture tissue in theseconfined sites are needles inserted through a trocar sheath or devicesin which a retractable needle is encased in a cannula. The needle onthese devices typically penetrates entrappod tissue. The hook on theneedle snares the sutures in the recess and the needle is retracted backthrough the tissue. These devices are bulky, and force is oftennecessary to engage the suture. Tissue can be dense and difficult topenetrate with a needle. In some of the instruments that are elongatedto reach the surgical or biopsy site, the shaft and posts are not rigidenough to endure the force that must be applied to penetrate the tissue.Many times this force is necessary because the needle is not sharpenough to easily pierce the dense tissue. The instruments are sometimesheavy and burdensome, which restricts the surgcon's maneuverability andcauses fatigue. Use of undue force in the suturing procedure retardshealing, and large needle heads and cannulas restrict the physician'svision. Also, the instruments are often not sufficiently elongated toaccommodate adequate retrieval or rotation of the suture material.

A known ligature provides a series of gauged needle sizes that allowsuturing of tissue. However, these needles are used primarily inshoulder surgery due to the length of the devices. This ligature isdesigned with a sliding member that is unstable due to frictionencountered during penetration into the tissue. The distal end of theligature includes a recess that holds the suture in place. The frictionencountered during penetration forces the recess open, exposing sharpedges that sever tissue. The prior art is not well suited for endoscopicsurgery and cannot be adapted to these procedures without compromisingthe integrity of the stainless steel shaft and post on the instruments.

German Patent 2,532,242 illustrates a fixed rounded needle having aninternal sleeve which is shiftable to engage a suture in a cut-outwithin the needle. However, the opening for entry of the suture remainsexposed due to the track for the internal sleeve leaving notches open onthe periphery of the stationary needle. These open notches can engagethe tissue and cause trauma.

Accordingly, it is an object of this invention to provide surgeons witha device that minimizes trauma to tissue during the suturing procedure.The present invention provides a needle with a hook that recedes into aprotective sheath, which allows accomplishment of the above objective.

SUMMARY OF THE INVENTION

The foregoing problems are solved and technical advances are achievedwith this invention. Surgeons may use the present invention not only toemplace sutures into tissue, but sutures may be withdrawn with thisdevice. A loop may then be tied and the process may be repeated untilthe desired stitching pattern is achieved. The suturing process may becompleted with the use of the one instrument.

The endoscopic suturing needle of the present invention provides animproved elongated thin needle that increases the speed of the suturingprocedure. The present invention is preferably approximately 111/2" inlength. The handle is preferably made of a lightweight plastic moldedmaterial. There is a thumb switch that slides forward on the handle thatextends and retracts the suture needle assembly. The needle assemblyextends from the handle through an outer tube. A stiffener tube isconnected to the outer tube to ensure rigidity. The needle is angulatedto achieve ease in suturing. The end of the outer tube is flattened andforms a protective sheath. The suture needle has a sharp tip and is 1.1mm in length. There is a rounded hook that is approximately 4 mm fromthe tip of the needle. This hook evolves into a recess. The distal endof the hook recedes into the lumen of the protective sheath. Thisretraction capacity allows encasemerit of the suture prior totransversion of the tissue. After the suture is secured and loaded inplace, the needle penetrates the tissue. Once optimal placement of thesuture is attained, the thumb switch on the handle slides forward underpressure of the thumb, and the needle and hook extend out of theprotective sheath. This disengages the hook on the needle and allows thesuture to be easily released from the recess. The hook on the needle maythen be re-engaged by retraction, thus assuring an eased withdrawal ofthe needle. This process is repeated to create the desired stitchingpattern.

These and other objects and features will be apparent from the followingdetailed description when read in conjunction with the drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional elevational view showing the assembly of thecomponents of the apparatus of the present invention.

FIG. 2 is a detailed view of the distal tip, showing the curvature ofthe needle.

FIG. 3 is a detailed view of the distal end of the outer tube throughwhich the needle extends, showing its changes in cross-sectional shape.

FIG. 4 is a detailed view of the distal end of the needle.

FIG. 5 is an assembly view showing the needle and how it fits beyond theouter sleeve.

FIG. 6 is a sectional view along lines 6--6 of FIG. 6.

FIG. 7 is a sectional view along lines 7--7 of FIG. 6.

FIG. 8 is a sectional elevational view showing the needle detent system.

FIG. 9 is another view of the detent system shown in FIG. 8, showing howthe detent is defeated.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The apparatus A is shown in FIG. 1 in part section, It features anelongated handle 2 that can be made from a variety of lightweightmaterials so as to minimize fatigue for the surgeon in using theinstrument. The handle 2 can be made in one piece or in severalcomponent pieces, In the preferred embodiment the handle 2 is hollow toaccommodate push block 4, Push block 4 extends through handle 2 to apoint where it is connected to thumb switch 6, Thumb switch 6 has aplurality of ridges 8 to minimize slippage in operation of the switchbetween its open and closed position. The open position of switch 6 isachieved by pushing it distally toward distal end 10. Conversely, theclosed position is achieved by moving switch 6 towards proximal end 12.

Push block 4 is connected to an elongated needle assembly 14. This canbe accomplished in various ways as shown in FIGS. 8 and 10. The needleassembly 14 extends through an inner tube 16. Inner tube 16 terminatesat a distal end 18 (see FIG. 5). Inner tube 16 extends through outertube 20, as shown in FIG. 1. The outer tube 20 extends from withinhandle 2 to a distal end 22, with inner tube 16 extending beyond distalend 22.

It should be noted that in operation of the apparatus of the presentinvention the outer tube 20 is stationary, as is the inner tube 16. Theonly moving parts are the switch 6 connected to push block 4, which isin turn connected to needle assembly 14. A loose tube 24 supported byhandle 2 circumscribes needle assembly 14 and acts as an extension stop,as shown in FIG. 8.

The handle 2 has a depressed segment 26 to facilitate grip of theapparatus A while switch 6 is moved between open and closed positions.It should be noted that the profile of outer tube 20 to its distal end22 is rounded. Similarly, the profile of inner tube 16, as it extendsthrough the outer tube 20 and a portion beyond, is also rounded.Referring to FIG. 3, it can be seen that the profile of inner tube 16changes near its distal end 18. At its distal end 18 the profile hasbeen flattened and in cross-section has a generally race-track shape, asindicated in FIG. 7. At a transition 28, the profile of inner tube 16changes to a rounded profile (FIGS. 5 and 6).

The nature of the fit between the needle assembly 14 and the isillustrated in FIGS. 5, 6, and 7. As seen in FIG. 5, at the point wheresection lines 6--6 appear, the profile of inner tube 16 is rounded,while the needle assembly 14 extending through at that portion is flatin a generally rectangular cross-section 30. After transition 28, theprofile of inner tube 16 assumes the profile of the needle assembly, asshown in FIG. 7. The needle assembly 14 continues beyond distal end 18of inner tube 16. The distal end 32 of the needle assembly 14 isillustrated in FIG. 5. There are a pair of sharpened edges 34 and 36which lead to a tip 38. Proximally of the sharpened edges 34 and 36, theedges 40 and 42 are more rounded and dull.

Referring now to FIG. 4, it can be seen that the needle assembly 14 hasa recess 44 near its distal end 32. The recess 44 is adjacent andabutting the hook 46, which is disposed for contact with distal end 18of inner tube 16 when the needle assembly is in the retracted position,as shown in FIG. 5. At the same time, while needle assembly 14 isretracted, a taper 48 also connects with edge 50 on inner tube 16 (seeFIG. 5). Clearly the width of the distal end 32 of the needle assembly14 exceeds the width of inner tube 16 at section lines 7--7 of FIG. 5.Therefore, the contact of the hook 46 and taper 48 with inner tube 16defines the retracted position of needle assembly 14 with respect toinner tube 16. When in such retracted position, the recess 44 isliterally within inner tube 16 such that the opening is blocked. Thisallows retention of the suture as the needle tip 38 penetrates thetissue. The reaction forces from the tissue as the needle tip 38 isbeing advanced also act to hold needle assembly 14 in the retractedposition, as shown in FIG. 5.

As shown in FIG. 5, surface 50 is located more proximally than distalend 18 of inner tube 16. A curved edge 52 is thus formed. The use of thecurved edge is necessitated by the expansion of profile of the distalend 32 at surfaces 40 and 42. In order to allow retraction of distal end32 sufficiently into inner tube 16 so as to close the recess 44, theopposite end of inner tube 16 needed to be cut away back to surface 50.It should be noted that there is a close fit between curved surface 52and the distal end 32 of needle assembly 14. This may include a smallstep since curved surface 52 rides above distal end 32. Alternatively,distal end 32 can be thickened so that on retraction of needle assembly14, the distal end 32 abuts edge 52 so that a smooth surface ispresented to avoid trapping any tissue during the procedures involvingthe apparatus A.

Referring now to FIG. 2, the overall shape of the distal end 18 of innertube 16, as well as needle assembly 14, is illustrated. As shown in FIG.2, there is a curvature 54 to improve visibility and ease the suturingprocess while using the apparatus A. The profile of the inner tube 16during this curved portion 54 is preferably round. Toward the distal end18 of inner tube 16, the profile transitions to flat at point 28 (seeFIGS. 2 and 3).

It is desirable to keep the suture (not shown) firmly ensconced withinthe recess 44 as the apparatus A is being withdrawn from the tissue.This pulling force on the apparatus A via handle 2 can have a tendencyto make the distal end 32 disengage from the distal end 18 of inner tube16. Should there be any extension of the needle assembly 14 with respectto inner tube 16, the recess 44 would become exposed, thus releasing thesuture. This would be extremely undesirable. To counteract such apossibility, a positive lock assembly L (see FIG. 8) is provided withinhandle 2. As previously stated, handle 2 has a switch 6 which isconnected to a push block 4. Needle assembly 14 is formed into a loop 56through which extends push block 4. One component of loop 56 isextension member 58. Extension member 58 is cantilevered and is doubledover at point 60 for additional strength. The member 58 is bent so thatit rides on the inside wall 62 of handle 2 where it necessarily runsinto detent 64. With the cantilevered end 60 abutting detent 64, furtherextension of needle assembly 14 with respect to inner tube 16 isimpeded. However, if a sufficient force is placed on thumb switch 6,which is in turn transmitted to push block 4, push block 4 continues tomove and starts to bear on inclined extension member 58. Since the pathof push block 4 is predetermined because it moves in a slot (not shown)aligned with the longitudinal axis of handle 2, there comes a time whena sufficient force is transmitted through push block 4 to bear onextension member 58 and begin to deflect it angularly about point 66.Eventually, sufficient angular movement results so that end point 60 ismoved around detent 64, allowing further extension of needle assembly 14with respect to inner tube 16. As long as the surgeon grips the handle 2without moving switch 6, while he is removing the apparatus A, anytendency of needle assembly 14 to pull out of inner tube 16, thusreleasing the suture (not shown), will be resisted by the interaction ofend 60 of member 58 against detent 64.

The apparatus of the present invention has several advantages over thoseof the prior art. The distal extremity of the needle assembly 14 is flatand thin, and the distal end 18 of the housing is flat, thus presentinga low profile. The housing then transitions at 28 to a rounded profile.Rigidity is maintained by the stiflenet tube 20. The sharp edges 34 and36 allow easy penetration into tissue, minimizing potential trauma. Thesimilar flat profiles presented by the distal end 32 of the needleassembly 14, as well as the distal end 18 of inner tube 16, eliminateirregular surfaces which could cause tissue trauma. The recess 44 isenclosed within inner tube 16 to avoid presentation of notches whichcould tear the tissue upon movement of the apparatus A. The sharp edges34 and 36 make precision entry into the tissue possible, while the rapidtransition to a rounded profile stretches the tissue, avoiding furthertissue trauma. The curved segment 54 promotes visibility and ease insuturing when using the apparatus A. Accidental release of the suture isprevented due to the lock mechanism L shown in FIGS. 8 and 9. Therelative movement of the needle assembly 14 with respect to inner tube16 is controlled in both extension and retraction. Since the distal end32 of the needle assembly 14 has a greater profile than the distal end18 of inner tube 16, inner tube 16 effectively acts as a travel stopupon retraction. On extension, the push block 4 engages the proximal endof loose tube 24, as shown in FIG. 8, to prevent further outwardmovement.

The foregoing disclosure and description of the invention areillustrative and explanatory thereof, and various changes in the size,shape and materials, as well as in the details of the illustratedconstruction, may be made without departing from the spirit of theinvention.

I claim:
 1. An apparatus for endoscopic suturing, comprising:a handle;an elongated housing extending from said handle having breadth least oneside surface; needle means retractably mounted and extending beyond saidhousing for penetration into body tissue and for selective retention ofa suture against said housing; said needle means having at least oneedge surface; a portion of said needle means having a breadth at leastas large as the breadth of said housing, whereupon when said needlemeans is retracted toward said housing, it cannot be fully drawn intosaid housing; and said at least one edge surface of said needle meanspositioned in substantial alignment with said side surface of saidhousing, to present a smooth transition therebetween when said needlemeans is retracted toward said housing.
 2. The apparatus of claim 1,wherein:said housing is tubular; said needle means extends through andbeyond said housing.
 3. The apparatus of claim 1, furthercomprising:switch means on said handle to selectively extend and retractsaid needle means with respect to said housing; lock means on saidswitch means to prevent extension of said needle means out of saidhousing as the apparatus is withdrawn from tissue while engaging asuture.
 4. The apparatus of claim 3, further comprising:means fordefeating said lock means selectively operable by actuation of saidswitch means.
 5. The apparatus for endoscopic suturing of claim 1,further comprising: switch means on said handle to selectively extendand retract said needle means with respect to said housing; and lockmeans internally of said handle and operably connected to said switchmeans for automatic retention of said switch means within said handleonce said switch means is moved into position retracting said needletoward said housing.
 6. An instrument comprising:a handle; a housingmounted to said handle and having a breadth, distal and proximal ends atleast one side surface; a needle mounted within and extending distallyfrom said housing; a suture having a plurality of ends; means on saidneedle to accept said suture intermediate its ends; said needleselectively retractable toward said housing for retaining said suturebetween said housing and said needle, as said handle is moved withrespect to body tissue; said needle having at least one edge surface; aportion of said needle having a breadth at least as large as the breadthof said housing, whereupon when said needle is retracted within saidhousing, it cannot be fully drawn into said housing; end said at leastone edge surface on said needle positioned in substantial alignment withsaid side surface of said housing, to present a smooth transitiontherebetween when said needle is retracted toward said housing,
 7. Theinstrument of claim 6, comprising:means to retain said needle in aretracted position while the instrument is pulled through tissue by saidhandle, thereby securing the suture; switch means on said handleoperatively engaged to said means to retain for selective defeatingthereof to allow extension of said needle with respect to said housingfor release of said suture.
 8. A method of endoscopic suturingcomprising the steps of:extending from a housing a needle having abreadth over at least a portion thereof at least as small as saidhousing; trapping a suture with a hook formed on said needle byretracting said needle towards said housing; placing at least one edgelocated on seed needle in close alignment with at least one side surfaceon said housing, by virtue of seed retracting, to form a smoothtransition; and moving said housing and needle with said trapped suturewith respect to the tissue.
 9. The method of claim 8, wherein saidtrapping step further comprises:moving an open segment of said hookwithin said housing.
 10. The method of claim 9, furthercomprising:presenting a smooth transition between said needle and saidhousing upon trapping said suture for minimizing tissue trauma duringsaid suturing by providing both said needle and said housing withsubstantially aligned profiles at said transition.
 11. The method ofclaim 10, further comprising the steps of:actuating said needle by aswitch on a handle mounted with said needle; latching said needle in aretracted position to avoid accidental release of a suture; selectivelyovercoming said latching to allow said needle to disengage the suture.